1. Field of the Invention
The present invention relates to imaging apparatus, image processing unit, method thereof and recording medium for determining the depth of an object to be imaged. More specifically, the present invention relates to apparatus and method thereof for obtaining information as to the depth of an object based on parallactic images of the object.
2. Description of the Related Art
In order to obtain information about the location of an object, a method known as a parallactic imaging is used, which is based on a model of stereo-viewing by two human eyes. In this, two cameras are arrayed so that parallactic images viewed from two different points are obtained, and the depth is thereby measured. The displacement of the images of the object is detected because of the difference between the viewpoints, so that the distance from the camera to the object can be calculated by the triangulation principle using the displacement of the images and the focus length of the lens of the camera. In this, Japanese Patent No. 2611173, issued on Feb. 27, 1997, discloses a method in which the position of a moving object is determined using at least three imaging devices.
However, even when two cameras are used, due to a limit of the angle of vision of their lenses, the dead angle or “blind spot” of the parallactic images is in the direction of the moving object. Therefore, it is difficult to accurately determine depth information of an object through a wide visual field. Furthermore, according to the method disclosed by the aforementioned Japanese Patent No. 2611173, at least three imaging devices are required so as to establish the coordinates of the moving object. As a result, the devices and equipment become too large and complex, and the calculation costs are too high.